Let-off for looms



March 4, 1930. w. H. BAKER LET-OFF FOR'LOOMS Filed June 21, 1928 4 Sheets-Sheet l lllilk March 4, 1930. w. H. BAKER. 1,749,120

LET-OFF FOR LOOMS Filed June 21. 1928 4 Sheets-Sheet 2 March 4, 1930. w. H. BAKER LETY-OFF FOR LOOMS Filed June 21, 1928 4 Sheets-Sheet 3 March 4, 1930. w, A I 1,749,120

LET-OFF FOR LOOMS Filed June 21, 1928 4 Sheets-Sheet 4 elements, shown" detached from the general "beam-7; in addition, they ShOW a bracket 8' cap ' Patented I ATEN E iW ILIiIAM 11.: 1344x3113,v or MONTREAL, QUEBEC, CANADA LET-DEF FOR LOOMS' a 1 Application ,"filed iuneai The invention has relation to positiveiletoffs ofthe class in which the action of; the 'let- I offmechanism ofaloom in producing warpdelivering rotation? of a" warp beain is gov- {5 erned" by the'tension of that portion of" the warp extending forward through theloom towardthe active Weaving instrumentalities.

"The inventionconsistsin a let-offmechanis'm, of novel and improved construction in- '10tendedtoineet' all the requirements known f wine toj'be 'essentialfor good weavingf f,Theconstructional details of a let-off rembodyiag the principlesof the invention admit 'ofbeing varied in practice.

a Two ,illustrat've embodiments of the said principles are shown in the accompanying drawings, in which latter-e M j "Fig; 1 is a,view*showing o'ne-of'the said embodiments in side elevation,partly in sec- Q'tionL "In this View the-let-ofi mechanism is represented as employed in connection 2 Itheright-handside of a loom.

' "Fig.2 isaview 'the'reof in rear'eleva'tion,

Fig; 3; isa 'partlysectional view ofcertain mechanism.

Figa tis a side elevation showing an em 1 b-odimentproviding for adjustment of the i transmission-gear assembly to suit, warpbeams of difierentlength. In thlSVlGW the I let-offinechanism is represented as'employed in connection with, the left-hand side of a 'gFig. 5 a rear elevation View ofportions '3 ofthis' secondembodiment; f f g *fFigs. IG a'n'd 17are viewsin side "elevation. and rear elevation,- respectively, of the adjustabl'e warp-beam support of Figs. 4-and 5.;

I "v Referring first toFigs. 1 and f thedrawings,"theseviews show a portion offlone'side- 'tion'of'the-loom crankshaft2, mounted in a be'a'ringon said side-frame, and a :handwheel 3ion said crankshaft. They'show also a bracket 4: projecting rearward from the said f side-frame and provided with an open slotted bearing 5 receiving a journal 6 of a warp.-

' attached byimeans of bolts 9, 9, to the bracket fi' gprojecting rearward therefrom, and supthe said worm;

ratchet-wheel intoa fresh starting position,

1928. Serial Np. 287,336.

porting a back-bearer 10 to which the warp '11 passesfrom the warp-beam 7 The said back-bearer constitutes a definitely-located warp-guiding support from which the warp extends forwardly in the loom to the harnesses and other active weaving instrumentalities. It preferably consists of a roll which is journaled in a bearing provided in connection with the bracketBQ *The beamjournal 6iisshown as held in place within the slotted bearing 5 and in contact with the closed inner end thereof by means of an endcap 12, shown engaged with the outer end of the saidjournal and fastened to the outer side of bracket The means for actuating the ratchet-wheel 16 and the associated train (just described) for the purpose of turning the warp-beam to unwind warp therefrom, comprisesa pawl17 which engages the teethof ratchet-wheel 16,

a swinging pawl-carrier 18, a spring 19 for moving the said pawl-carrier backward to retract the pawl relative to the teeth of the and a rod 20, having a reciprocatory endwise movement imparted to it, in this instance by means of a crank'21' on the loom crankshaft 2, although the precise actuating means is not materiahthe said rod being provided with acollar 22 designed to engage with the'pawlcarrier in the stroke of-said, rod in one direction, so that when such engagement takes place the pa'wlcarrier is actuated to move the ,paWl forward from its starting position so as 93 to tu'rnthe ratchet-wheel to produce a turning ,movement of the warp-beam for warp-delivery purposes. s

As a convenient feature of construction,

the pawl-carrier 18 is sleeved upon the shaft I 161 of ratchet-wheel 16, sothat it swingscon- 'centrically with the said ratchet-wheel. The

pawl 1'? is carried by one arm of the swinglar 22 provide for positive actuation of the pawl carrier and pawl from starting posi! tion in the direction forproducing rotation of ratchet-wheel 16 in the direction for occas'ioning rotationof the warp-beainforwarps delivery. i

In accordance with the invention, for gov erning'theactionof the letoif mechanismby the tension of that portion of the warp GK-r 25 tending from the warp-beam and forward, Y 'through the loom I employ a tension-com trolled member between whichand such portion of the warp there is interengagenient.

Such tension-controlledmember is or maybe of the same general character as the-whip rolls which have been employed heretofore in other mechanisms of the same class ofilet- The said tenslon-controlled member IS offs. combined operatively with the pawl-carrier 3 5 18 in manner to control the extent of the return stroke ofvthe said pawl-carrier and the pawl l7after a feed-movement thereof; with v aview, in particular, to varying the starting position of thepawl so as to cause the extent m of every feed-movement that is imparted to the pawl to be proportioned according to the state of'tension of the said portion of the warp at the time of such feed-movement In. the preferred mode of reducing of, the

45 invention to practice-the said tension-com.

trolled memberfwhip-roll) is combinedope'ratively withthe pawl-carrier for; the purpose stated by means of a pawl car'rier stop,

the position of which is determined through fiqgtheposition assumed by the whip-rollunder the control of the warptension.

The whip-rollshown inthe drawings com prises a warp-engaging member constituted by airo'll 23, supporting arms 24, and a rock 5 :shaft journaled in'bearings in connection with stands 251, mounted upon thebrackets 4.

The whip-roll is backed-up against the pressure of thezwarpby means of an expand p ingspiral spring, 5 acting against an arm' 2 3l-fixed upon the rockshaft25iofthe whip-v rollL: This vspring acts with a tendency to I rock the whip-roll so as to take up any slack in the portion of warp extending from the warp-beamand forward through the loom,

and so as to maintain such portion in a conspring.

stant state of tension. Excess movement mi 1 to der the action of spring '30 is prevented by contact of, the back of the said arm 31 with V a stop constituted by a washer and nut 32 upon a rod 33 extending from a fixed arm 34 projecting from bracket &.3 Thecspring sur- I s rounds the said rod between the said arm and "an rabutment 3 5 sleeved upon the'rod adjacentthe iix'ed arm 34. I The position of stop "32 may be varied, so as tovary the height capable "of being assumed by the roll 23, as c r r for varying the height 'ofthe sheet of warp 'atandforward of such roll, through ad- 1 justment of the saidstop 32 upon rod 33 in the direction of the length of such rod, or

to the opposite endof the rod-i 33 forthe. pur

pose of holding the rod in place in connection L with the fixed supporting arm 34. 'The'sead, v just1nent-ineans also enable the tension of the SPring SOtO beivaried. r

so i by adjustment of the nut ornuts 36, applied 7 In this 'instance the pawlcarrier stop 28, V

Fig 3, is iconstituted by a stop-collar 28 upon a rod 27,.suchicollar serving, as the case may be, either to prevent the pawl-carrienfrom making a return-movement: relatlve to the teeth of ratchetwheel 16, ortoperrnitting a 'returnunoyement ofthe pawl-carrier through the action of spring 19 to an-{extentdetermined. by the state oftension of the warp. Through theWhip-roll andconnections to the pawhcarrier stop the: stateof tension ofthe warp determines the position ofthe' said. stop 28, and therebyde termines whether the pawlafl I i r p carrier and pawl shall make a' return-movement to astarting position for a fresh warpdelivering feed-movement; and through deee Y termining also the extent. of return movement determines the location of thefstarting 7 position for the neXt feed m Vement of the pawl. Thus, according to the said state'of. I tension; either warp-delivery is suspended or the V extent of tu'rning movement communi- 'cated-to the ratchet wheel 16;.andft-he warp beam by the pawl 17 in itsensuingadvance is proportioned suitably" to ,meet the require:

ments-of the moment. The-whip-rollis'icon- I 'nected to the stop by means of, an arm -26 extending from the ,rockshaft 25 and having engaged pivotally therewith the upper endjofthe rod 27, the lowerendof which extends through ahole provided in .the--pawl-Carrier alongside. that occupied by actuating rod; 20.

Theend of spring 19v opposite fromthe end 7 engaged with the pawl-lever. is; engaged inf the present instan'ce withia-collar29 that is adjustable uponthe IOd Q-ZIGHgthWlSB ofsuch; rod,a-such collar servingras a convenientpoint ofatta'chnieiitmfor suchend of the.

In operation, the guide 23'ofT theQ whip-roll not only, determinesthe height f the sheet 'of; warp extending; forwardly through the: loom-harnessesand reed toward 4 creaseln the diametenof the wound yarn- "the loom breast-beaim'gbutbeing subjected" to pressure dueto the-tension Y of such sheet ofivarp'is afiected m'orieor less ast'o its own Position "t i i I1-'- Changeso infthe position of Y the -whip-roll are accompanied bychanges; in the :position of pawl-carrier I stop28, either suspending areturn-movement of the pawl-carrier and -pawl after a feedmovement thereof, or resulting ;in {COFFE- turn movementsof the pawl-carrier and pawlsponding variations in the extent ofthereafter "forward feed movements thereof,; and consequently modifying theextentof the warp-delivery.

The T employment of a back-bearer cons tie I 'tutedby agui'de onroll, as. 10, intern1e diate the warp-beam andxthe Whip-roll prevents theiangle of incidence of the warp, uponi the, whip-roll from being altered througlr'demass carried by', the, warp-beam, Consequently,-by reason oftheline of pull ofthe warp at the whip-roll remaining unchanged from first to last, the'inter-action, between the warp and the whip-rollis unaffected by ditferencesin the diameterof the yarn-mass uponthe beam.{Iniordinarvpractice with other forms ofletl-oif mechanisms, it-usually is necessary to ;ma, l e;,one or more adjustmentsas the warp 1S paid'olf from the warp beam, in order to compensate forthe reductionof the warp-diameter.

Inthe embodiment of the principles of the invention that is illustrated in. Figs.v 4 to 7, the brackets 4 andf 8 of'Figs. 1 and 2are replacedby a stand-41 and a bracket 42.

Stand 41 is attached by means of bolts 91,

9,1, to the loom-side 1 and a main web-per tioirth ereof exten ds from said loom-side inwardly'crosswise of the loom. The sa1dweb-.

' portion is slotted as at 411, 411,1Fig, 5, trans versely of the loomto' permit of adjustment "of bracket 42 thereon 'inthe direction'of the jp'ortedoin working relations-with worm-gear 13 of the warp-beam; :The slot 144in bracket "42 permits the worm-shaft and worm to be ;--'adjusted toward and: from the axis of the [warp-beam, tosuit the diameter of wormgear 13,]so as to enable the thread of the.

I i worm to beplaced properly in mesh with the teeth ofthe worm-gear. Bevel-gear 15 is mounted on the, transversely-extending let-off shaft 161 between V the bevel-gear 151 of the worm-shaft and the flat Web of bearing-bracketl42fi Forthe purpose ofcausing the bevel-gear l5'to rotate in unison with the let-off shaft, .while providingifor shift of such bevel-gear lengthwise of the let-oil shaft into different-working positions, a lon git-udinally extending splineor groove 145,

Fig. 5, is provided in connection with the let-off shaft." r

i .As will be perceived, the/described con-- structiori permits bracket42 and itsbearing for the corresponding journal; of warps beam to be adjustedtransverselyof the loom. into aposition :tosuit the length of warpbeamdesired to be'used; and provides also foradjustment in company therewith of the assembly of gearing providing for transmission of motion from the let-off shaft to the warp-beam for'letting-off purposes.

, In orderstoenablethewarp-beam to be turned manually by a weaver or loom-fixer, asfor the purpose of paying-out warp therefrom, or rewi'nding it thereon, I may pro'- vide for the removable application of. a crank-handle, as 162, Fig. 2, to the outerend. of shaft-l61 5 In this-instance the said shaftend is squared, to lit a square socket inthe crankshandle. I What is claimed asthe invention is v1. Ina loom, let-.ofi mechanism COIIIPI'IS'. ing a ratchet wheel and mechanism connected therewith for imparting turning movement to I for yieldingly restoring said pawlrcarrier and pawlto starting position, means for actuat-I ing said pawl-carrier and pawl from such positionto rotate the ratchet-wheeha back bearer to which the warp passes onits'way fromthe Warp-beam and around which the arp changes direction in going totheweavinginstrumentalities;of the 100111, a springactuated warp-engagingmember located toward the front of the loom relative to the said back-bearer controlled as to itsposition by the warpten'sion,'and a rockshaft mounted in, advance of the said roll, and fromwhich arms extend rearwardly for the support of the said-warp-engaging memberand another arm extends downwardly and has connected therewith means through which the said starting; position is, determined conformably with the posit on assumedbyrthe said mem ber "under the control of the warp-tension,

' L 2. Loom" whip-roll devices comprising'a rocks'haft, arms projecting rearwardly from said rockshaft, awarp-engaging member carried bysaid arms and receiving the pressure of the warp-on its *way to the weavinginstrumentalities, an arm afiixed to the said rockshaft, a rod, an expansion spring sur- 1 rounding saidrod andacting against said arm toswing the Whip-roll in opposition to thepressure of the warp, ,and adjustment f'means for varying the tensionof'said spring.

3; Loom whip-roll devices comprising a 'rockshaft, arms projecting-rearwardly:from

said Irockshaft, a vWarp-engaging member earned by said arms andreceiving the vpressure of the warp on-its way to the weaving instrumentalities, an arm afiixed to the said rockshaft, a rod having thereon a stop which limits theextent of the swing of the said arm, an expansion spring v surrounding said rod and acting against saidarm to swing the whip-roll in opposition to the pressure of the warp, and adjustment means for, varying the tension of said spring.-'

4. Loom let-off mechanism comprising, in comb natlon, a let-off shaft extending transverselyof a loom, means for actuatingsaid shaftfor letting off purposes, a warp-beam support adjustable transversely of the'loom to suit the length of the warp-beam placed in the loom,and gearingby which movement 5 vis transmitted from the said let-off shaft to shaft an'd-relativethereto.

the beam to unwind the 'warp from the latter as required in the weaving, said'gearing adjustablewith said support lengthwise of the 5. Loom let-off mechanism comprising, in

combination, alet-oifshaft extending transto turn inunison therewith and adjustablelengthwise, on the shaft as the warp-beam support is adj usted," anda" transmissiomge'aring assembly conn'ecting'said wheel with the warp-beam and carried by the said support.

' 6. Loom let-off mechanism comprising a I warp-beam, a worm-gear operatively com-; b1nedtherewith, a worm engaging with sald worm gear, a ratchet-wheel combined with said worm, an actuating pawl, a pawl-carrier, means for yieldlngly urging said pawl-carrier and'pawl toward starting position, a yieldingly-actuatedwhip-roll, a long'itu'dinally-movable rod operativel-y combined with the whip-roll and carrying a pawl-carrier stopwhich defines the starting position-' of whip-roll arm" and carrying a shoulder for i a. I engagement, with the jpawl-carrier to. define 1 I I the said star-ting position,'and a reciprocating rod equipped forengaging said pawl-carrier in movement of the rodinonedirection and thereby. actuating the pawl-carrier from said starting position :so as to produceiunwinding rotation of the warp-beam, .both rods'guided their reciprocation 1 8. .Loom-let-off mechanism comprising a by the pawlscarrier in movements. I

loom shaft, a crank combineditherewith, a

warp-beam, a worm gear combined therewith, a worm engaging wlthsald worm gear, a ratchet-wheel GOIIlblIlGCl wlthsaid worm, an

. actuating pawl, a pawl-carrienga yieldingly actuated whip-roll, a longitudinally-movable" 1 'rod combined with the whip-roll and having I a pawl-carrier stop which defines the starting position of the pawl-carrier and pawl, a rod connected with and reciprocatedby the crank aforesaidandhaving means'forengaging the pawl-carrier in movement of the rod in one 7 V n f direction, to cause the pawl to advance the ratchet-wheel and iwarpj-beam for the deliv ery of warp,'*and a spring connecting the pawl-carrier with thesaid rod to urge the pawl-carrier and pawl vyieldingly toward starting position.

- 'WILLIAM'H- sAKER I i 13 i p the pawl-carrierandpawl, and a reciprocat-,

ing rod having meansfor engaging said pawl-' QELI'IlBFiH movementof the rod in one direction,'to1cause the pawl to advancetheratchetwheel andwarp-beam for the delivery of war 7 In loom let-off mechanism comprising a warp-beam actuating ratchet-wheel, an ac tuating pawl, a 'pawl-carrienmeans for yield ingly urging said pawl-carrier and ,pawl reverselytowardstarting position, a 'yieldinglyactuated whipV-r'olhand a whip-roll arm, the combination with'the said elements, of a 1011- gitudinall-y movable rod connected with'said 

